The invention relates to a silage cutting machine with a U-shaped holding frame which can be mounted on a rack and moved up and down on the latter cutting tools configured as knife-like, rigid cutting blades which can be reciprocated by drive means are mounted on both sides of the rigid holding frame.
Silage cutters serve for cutting blocks of silage, especially from flat silos. Silage cutting machines are usually used as attachments for farm tractors or other similar vehicles, and in that case must assure, on the one hand, that the highest possible cutting power will be applied by the drive means to the cutting blades. On the other hand, on account of the given limits on the total weight of the tractor, the silage cutting machine must be as light as possible in order to permit the highest possible payload of silage.
Conventionally, silage cutting machines are constructed such that, for the production of a precise cut in the silage, the cutting tools on the lateral limbs of the holding frame members as well as on the front cutting mechanism are configured in two ways. Either simple cutting blades which by means of working cylinders held laterally at the front end of the lateral limbs of the holding frame cut out the silage block by a saw-like drawing back and forth of the cutting blades, or the cutting blades of the front cutting mechanism are joined to the lateral cutting mechanisms by flexible corner connecting means.
Also it is known to construct the cutting tools as double-edged tools, one cutting blade being fixedly mounted and the other being drawn back and forth. Also, the driving force is produced in part by a single actuator mounted on the front limb of the holding frame, the vertical movement of the working cylinder being converted by a connecting means as well as lever arms to horizontal knife blade movements. In this case the pulling force is transmitted, through bell cranks and other levers, from the front cutting blades to the side cutting blades.
This configuration calls for a complex design that is liable to give trouble and increases weight. It is disadvantageous that the driving means and the hydraulic lines have to be mounted in the working area of the cutting mechanism.